The Fukui District Court on Tuesday issued an injunction to prevent the restart of two reactors later this year, rejecting regulator's safety approval for the facilities.
The court ruling is the second in less than a year against utility Kansai Electric Power, which had sought to restart reactors 3 and 4 at the Takahama plant in Fukui prefecture - home to about a dozen reactors.
According to Japan's public broadcaster NHK Television, the ruling stated that safety at the plant west of Tokyo could not be assured and the regulator's standards "lack rationality."
Local residents had sought an injunction, arguing that restart plans underestimate earthquake risks, fail to meet tougher safety standards and lack credible evacuation measures.
Blow to the prime minister
The court's decision will delay plans by Prime Minister Shinzo Abe to restart the country's 48 nuclear reactors, all of which are currently offline due to the 2011 nuclear accident at the Fukushima plant.
Kansai Electric said it would appeal the decision, adding, however, that it could mean months, even years of delays and hundreds of millions of dollars in losses for the utility.
For the Abe government, resuming nuclear power - which supplied nearly one-third of Japan's electricity before Fukushima - is crucial to lift the world's third-biggest economy out of two decades of stagnant economic growth.
uhe/pad (AP, Reuters)